What role does ultraviolet light play in ozone depletion?

Ultraviolet light plays a crucial role in ozone depletion primarily by breaking down chlorofluorocarbons (CFCs) and releasing chlorine. CFCs are stable molecules that, while safe at ground level, become problematic when they reach the stratosphere. There, they are exposed to ultraviolet radiation, which provides the energy needed to break the molecular bonds in CFCs. This process releases chlorine atoms, which are highly reactive and can catalyze the destruction of ozone (O3) molecules.

Each chlorine atom can facilitate the breakdown of numerous ozone molecules, leading to a significant thinning of the ozone layer over time. This mechanism underscores the importance of ultraviolet light in exacerbating ozone depletion, as it is the initial factor that turns benign CFCs into potent ozone-depleting substances. Understanding this process highlights the need for regulatory measures to limit CFC emissions and protect the ozone layer, as its depletion can result in higher levels of harmful UV radiation reaching the Earth’s surface.